Hmm... New Idea? or do I smell what tom is up to?

[Butterfingers]

Whats the best way to reduce the behind the ball pressure in a fixed volume system without doing anything to the valve itself? Also, how do we lighten the bolt without using delrin?

Change the volume...

How do we change the volume without modifying the valve?

Make the bolt have a bigger ID.

How do we change the ID?

Mill out some metal from the front end of the bolt leaving a bit of metal at the lip end of the bolt to guide the powertube. Then you press fit a bigger powertube piston to match the ID in the front. This will also allow you to use a bigger foamie.

What do you think new idea or old news?

[AGD]

Butter,

Not a bad idea and it would work. Problem is that the bolts would not retro to the old valves so there would be a limited market. We did think about boring out the bolt and putting a delrin sleeve inside to displace metal but it would make the catch area weak. Keep thinking it is a good idea.

Agd

[Butterfingers]

I am gonna draw it out to eliminate the confusion.

This design will retro to older mags and (perhaps)retains the strength of the catch area.

Here's my quick hand sketch...

Got a little distorted from rotation and resizing. Use Imagination :)

[Butterfingers]

Insert delrin in void if desired. I don't think its necessary the metal on the back of the bolt and the powertube piston should provide enough stabilization. Drill out stem to reduce wt.

I guess the design would be called a tapered ID.

[Potatoboy]

Butter- seems like a good idea, good enough that I edited the image to make it a little more readable. (and a much smaller file size)

[Bad Dave]

Planet eclipse used to mill some of the base of the bolt, the area that contacts the bumper like a circular channel which saved a bit of weight, could be done on every agd bolt.

[Restola]

you all got to have fun drawing and i didnt. so i drew.

http://home.earthlink.net/~restola/bolt.jpg

[TheTramp]

Seems like a good idea but how much more volume would you really get? Wouldn't you need a bigger air chamber as well. We know that that didn't really improve anything.

[Butterfingers]

You would not need a bigger air chamber because an automag is a fixed volume system. Air is cut off from supply before firing.

The more volume you add in the path of the air the less the pressure would become. In the normal automag chamber pressure is fixed at 400 psi. By the time it gets to the ball it has expanded through the volume of the bolt and the powertube. Tests show the peak on ball pressure is only 60-70 psi. Pressure is inversely proportional to volume, if you increase the volume the pressure must decrease.

As for how much it will decrease the pressure thats speculative and will require further tests. The advantage of this bolt design is not primarily pressure. It is weight. By milling out the core you essentially have a bolt that is much lighter than the normal bolt. A superbolt sans delrin.

The smartmag you speak of didnt impove anything because it was poorly designed. It didnt work because it slowed the cycle down to the point where the valve became "out of time" and "out of sync."

Increasing the volume of the bolt will acheive lower pressures via an increse in volume post chamber without slowing down the bolt, overworking the regulator, or messing up the efficency of the valve. When volume increases pressure decreases.

Think of it this way. For simplicities sake I will use numbers in multiples of 5 and 10. We have a 500 psi charge we dump it into an area 5 times the size it becomes 100 psi. This 100 psi will then push the ball.

The regulator and the valve system still charges the 500 psi as normal but the increase in volume through the area the air has to travel will decrease the presure.

I hope that explains everything well enough.